Performance Evaluation of Cellular Networks with Mobile and Fixed Relay Station

It is foreseen that the next generation of cellular network would integrate the relaying or multihop scheme. In a multihop cellular architecture, the users are not only able to communicate directly to the base station (BS) but can also use some relay stations to relay their data to the BS. These relay stations can either be the users´ mobile station (i.e. mobile relay station) or some low cost station placed at specific location (i.e. fixed relay station). The main objective of this paper is to compare the difference between the relaying network architecture with mobile or fixed relay station as well as their performance gain. At first, the different advantages and disadvantages for each relay station method are given. Then, the capacity gains of the two methods are compared with a dynamic system level simulator. For this we integrate the relay station into conventional cellular networks using the UMTS FDD air interface. The results show that under certain conditions the uplink capacity gain of 35% is readily achievable for both form of relay station.